decennium

We have much need to distinguish century from century and decennium from decennium.

He was occupied actively with teaching, but the dominant feature of the decennium was his assumption of the Darwinian doctrines.

The decennium extending from 1550 to 1560 was the good period of Ivan IV.

But with intellectual matters it is totally different; they change from century to century, nay, from decennium to decennium.